Basket delivery system

ABSTRACT

A delivery device for a collapsible medical device may include a handle and a delivery assembly having a compartment for receiving the medical device. A catheter member may extend from the handle to the delivery assembly. The catheter member may have a first portion with a first compliance value and a second portion with a second compliance value different from the first compliance value. An internally threaded member may be fixedly connected to the delivery assembly. An externally threaded member may have a first portion operatively connected to the actuation member and a second portion threadedly coupled to the internally threaded member so that manipulation of the actuation member causes axial movement of the compartment relative to the catheter member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the filing date of U.S.Provisional Patent Application No. 61/924,786 filed Jan. 8, 2014, thedisclosure of which is hereby incorporated by reference herein.

BACKGROUND

The present disclosure is related to prosthetic heart valve replacement,and more particularly to devices, systems, and methods for delivery ofcollapsible prosthetic heart valves.

Prosthetic heart valves that are collapsible to a relatively smallcircumferential size can be delivered into a patient less invasivelythan valves that are not collapsible. For example, a collapsible valvemay be delivered into a patient via a tube-like delivery apparatus suchas a catheter, a trocar, a laparoscopic instrument, or the like. Thiscollapsibility can avoid the need for a more invasive procedure such asfull open-chest, open-heart surgery.

Collapsible prosthetic heart valves typically take the form of a valvestructure mounted on a stent. There are two types of stents on which thevalve structures are ordinarily mounted: a self-expanding stent and aballoon-expandable stent. To place such valves into a delivery apparatusand ultimately into a patient, generally the valve is first collapsed orcrimped to reduce its circumferential size.

When a collapsed prosthetic valve has reached the desired implant sitein the patient (e.g., at or near the annulus of the patient's heartvalve that is to be replaced by the prosthetic valve), the prostheticvalve can be deployed or released from the delivery apparatus andre-expanded to full operating size. For balloon-expandable valves, thisgenerally involves releasing the entire valve, assuring its properlocation, and then expanding a balloon positioned within the valvestent. For self-expanding valves, on the other hand, the stentautomatically expands as the outer sheath covering the valve iswithdrawn.

In conventional delivery systems for self-expanding aortic valves, forexample, after the delivery system has been positioned for deployment,the annulus end of the valve is typically unsheathed and expanded first,while the aortic end of the valve remains sheathed. Once the annulus endof the valve has expanded, it may be determined that the valve needs tobe repositioned in the patient's aortic annulus. To accomplish this, auser (such as a surgeon or an interventional cardiologist) typicallyresheathes the annulus end of the valve, so that the valve can berepositioned while in a collapsed state. After the valve has beenrepositioned, the user can again release the valve.

In traditional deployment methods, the user operates a handle to causedistal or proximal movement of a catheter or other member within thehandle, resulting in relative movement between the prosthetic valve andan outer sheath covering the prosthetic valve so as to cause deploymentof the valve. For example, in a typical transfemoral delivery device, adistal end of an outer sheath surrounds the prosthetic valve, and aproximal end of the outer sheath may be fixed to a carriage within thehandle. Manipulation of the handle causes the carriage to moveproximally or distally, which in turn causes proximal or distal movementof the outer sheath. In a typical transapical delivery device, a distalend of an inner shaft may support the prosthetic valve, and a proximalend of the inner shaft may be attached to a carriage within the handle,while the outer sheath may be fixedly connected at its proximal end tothe handle. Manipulation of the handle causes the carriage to moveproximally or distally, which in turn causes proximal or distal movementof the inner shaft relative to the outer sheath. In both examples above,manipulation of the delivery device handle causes proximal or distalmovement of a carriage, which movement is translated along most or allof the length of the device, through either the outer sheath or innershaft.

BRIEF SUMMARY

According to one embodiment of the present disclosure, a delivery devicefor a collapsible medical device may include a handle having anactuation member; a delivery assembly having a compartment for receivingthe medical device; a catheter member extending from the handle to thedelivery portion; an internally threaded member fixedly connected to thedelivery assembly; and an externally threaded member having a firstportion operatively connected to the actuation member and a secondportion threadedly coupled to the internally threaded member so thatmanipulation of the actuation member causes axial movement of thecompartment relative to the catheter member.

According to another embodiment of the present disclosure, a deliverydevice for a collapsible medical device may include a handle; a deliveryassembly having a compartment for receiving the medical device; and acatheter member extending from the handle to the delivery assembly, thecatheter member having a first portion with a first compliance value andsecond portion with a second compliance value, the first compliancevalue being less than the second compliance value.

According to the present disclosure, a method for delivering a medicaldevice into a patient may include providing a delivery device includinga catheter member having a first portion with a first compliance valueand a second portion with a second compliance value greater than thefirst compliance value; advancing the catheter member to an implant sitewithin the patient; and at least partially releasing the medical devicefrom a compartment adjacent the catheter member.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present disclosure will now be described withreference to the appended drawings. It is to be appreciated that thesedrawings depict only some disclosed embodiments and are therefore not tobe considered limiting in scope.

FIG. 1 is a perspective view of a delivery device according to anembodiment of the disclosure with a handle shown in a partial cut-away.

FIG. 2A is a partial cut-away view of the handle of FIG. 1.

FIG. 2B is a cross-sectional view of the handle of FIG. 1.

FIG. 3 is a perspective view of a portion of an outer catheter member ofthe delivery device of FIG. 1.

FIG. 4A is a cross-sectional view of a distal subassembly of thedelivery device of FIG. 1.

FIG. 4B is an enlarged partial cut-away view of the distal subassemblyof FIG. 1.

FIG. 4C is an enlarged partial cross-sectional view of the distalsubassembly of FIG. 1.

FIGS. 5A-C are partial cut-away views of the handle of FIG. 1 atdifferent stages of deployment.

FIGS. 6A-C are partial cut-away views of the distal subassembly of FIG.1 at different stages of deployment.

FIG. 7 is a perspective view of an overlying sheath for use with thedelivery device of FIG. 1.

DETAILED DESCRIPTION

As used herein, the terms “proximal” and “distal” are to be taken asrelative to a user using the disclosed delivery devices. “Proximal” isto be understood as relatively close to the user and “distal” is to beunderstood as relatively farther away from the user. Also, as usedherein, the terms “substantially,” “generally,” and “about” are intendedto mean that slight deviations from absolute are included within thescope of the term so modified.

In traditional valve deployment methods, to facilitate translation offorce from the handle of the delivery device to an end of the catheter,particularly in the distal direction, the outer sheath or inner shaftthat is being translated may need to have a threshold amount ofstiffness, otherwise the distal motion of the carriage may not beproperly translated to the outer sheath or inner shaft. At least some ofthe disclosure provided herein may provide for valve deployment withlimited portions of the device experiencing tension and/or compressionduring delivery which may allow, for example, for the use of materialswith relatively high compliance.

For example, referring now to FIG. 1, an exemplary transfemoral deliverydevice 100 for delivering a collapsible prosthetic heart valve (or othertypes of self-expanding collapsible stents) is illustrated. Generally,delivery device 100 includes a handle subassembly 200, an outer catheter300, and a delivery subassembly 400, the structure and function of eachof which is described in greater detail below. As is described ingreater detail below, particularly in relation to FIGS. 5A-6C, thestructure of delivery device 100 may limit the length of outer catheter300 which experiences tension and/or compression forces during valvedeployment, permitting the use of compliant materials in theconstruction of the outer catheter.

FIGS. 2A-B show partial cutaway and cross-sectional views, respectively,of handle subassembly 200. Generally, handle subassembly 200 includes ahandle housing 210, a deployment knob 220, a center drive 230, a drivekey 240, and a drive screw 250.

Handle housing 210 may generally take the form of a hollow cylindertapered at a distal end thereof. Handle housing 210 may include a firstportion and a second portion, which may be individual pieces configuredto be joined to one another, for example by an adhesive. The first andsecond portions of handle housing 210 define an elongated interior space212, the elongated space being interrupted by first, second, and thirdinterior walls 214, 216, 218. Interior walls 214, 216, 218 may eachinclude an aperture in which a rotatable drive mechanism, such as centerdrive 230, is configured to fit.

Center drive 230 may generally take the form of an elongated cylinderwith a channel extending longitudinally therethrough. In the illustratedembodiment, center drive 230 is positioned within correspondingly shapedapertures in interior walls 214, 216, 218, such that the fit is snug butthe center drive is capable of rotation about its longitudinal axis.Center drive 230 may include a spur gear 232 having a plurality of teethextending radially outward from center drive 230. Spur gear 232 may bebonded or otherwise fixedly connected to center drive 230, or may beformed integrally with the center drive as a single monolithic piece.Spur gear 232 may be positioned between interior walls 216 and 218, andmay be sized so that an outer perimeter of the spur gear projectsoutwardly through a slot in handle housing 210.

Deployment knob 220 may generally take the form of a cylinder with atapered distal end rotatably coupled to handle housing 210. Deploymentknob 220 may include a ring gear 222 having a plurality of teethextending radially inward from deployment knob 220. Ring gear 222 may bebonded or otherwise fixedly connected to deployment knob 220, overmolded to an inner diameter of the deployment knob, or formed integrallywith the deployment knob. Deployment knob 220 may be positioned onhandle housing 210 such that the teeth of ring gear 222 interlock withthe teeth of spur gear 232. As a result, rotation of deployment knob 220relative to handle housing 210 will result in a corresponding rotationof center drive 230. Spur gear 232 may also extend partially into acircumferential slot on the inner diameter of deployment knob 220 torestrict the movement of the deployment knob longitudinally relative tohandle housing 210. Deployment knob 220 functions as an actuationmember, but it should be appreciated that other types of actuationmembers may provide the desired function other than a deployment knob.

Drive key 240 may take the general form of an elongated rectangularmember with a channel formed longitudinally therethrough. Drive key 240may have a transverse cross-section that corresponds to the transversecross-section of the channel in center drive 230, and may be sized tofit snugly within the center drive channel. As a result, rotation ofcenter drive 230 causes a corresponding rotation of drive key 240 andvice versa. Although the channel in center drive 230 has a generallyrectangular cross-section and drive key 240 has a generally rectangularcross-section, both the channel in the center drive and the drive keymay take other corresponding cross-sections, such as triangular orelliptical, which allow for transmission of torque between the members.

Lead screw 250 may take the general form of an elongated cylinder andmay be, for example, a torque cable. A proximal portion of lead screw250 may extend within and be secured to, for example by bonding or otheradhesive means, the channel in drive key 240. In this configuration,torque may be transmitted between lead screw 250 and drive key 240,while axial translation of the lead screw may cause correspondingtranslation of the drive key. Lead screw 250 may also contain a throughbore extending along its longitudinal axis configured to accept, forexample, a guidewire 360 therethrough. Guidewire 360 may exit a proximalend of handle housing 210 through a proximal aperture in the handlehousing. Lead screw 250 may extend through a channel in the distal endof handle housing 210 and further through outer catheter 300, describedin greater detail in relation to FIG. 3. A distal portion of lead screw250 may be threaded to interact with corresponding threading of a nut410, such that rotation of the lead screw with respect to the nut causesaxial translation of the lead screw in the proximal or distal direction,depending on the direction of rotation. The structure of nut 410 and theinteraction between lead screw 250 and the nut is described in greaterdetail below in relation to FIGS. 4A-C.

As noted above, the distal end of handle housing 210 may include achannel through which lead screw 250 extends. Still referring to FIGS.2A-B, a proximal end 310 of outer catheter 300 may be fixed within thechannel, for example by bonding or by adhesives, such that the outercatheter is rotationally and axially fixed with respect to handlehousing 210.

It should be noted that, with respect to handle subassembly 200 andcomponents thereof, the above description pertains to the illustratedembodiment. However, a number of variations may be made to handlesubassembly 200 and its components without varying from the scope of thedisclosure. For example, handle housing 210 has been described as beingformed of two portions. However, handle housing 210 may be formed of asingle portion, or more than two portions. Further, the particularshapes and configurations of the components of handle subassembly 200may be otherwise varied as should be apparent to one of skill in theart.

Outer catheter 300 is shown isolated in FIG. 3. Outer catheter 300 maygenerally take the form of an elongated hollow cylinder extending fromproximal end 310 (shown in FIGS. 2A-B) to a distal end 320. Outercatheter 300 may include a plurality of different zones. For example,outer catheter 300 may include a proximal zone 330, an intermediate zone340, and a distal zone 350. Proximal zone 330 and intermediate zone 340may have similar or approximately equal diameters, with distal zone 350having a greater diameter than both the proximal and intermediate zones.Proximal zone 330 and intermediate zone 340 may have different levels ofstiffness or compliance. For example, proximal zone 330 may be lesscompliant (or more stiff) than intermediate zone 340. As is described ingreater detail below with respect to FIG. 7, this configuration mayfacilitate the use of additional components to enhance accuracy duringdelivery and deployment of a prosthetic valve. Distal zone 350 mayextend to and cover a portion or all of delivery subassembly 400.Specific materials that may be used to form proximal zone 330,intermediate zone 340, and/or distal zone 350 include, for example,Pebax, nylon, stainless steel braid, Vectran, polyether ether ketone(PEEK), polytetrafluoroethylene (PTFE) and nickel titanium alloys suchas nitinol. Although any combination of materials may be suitable foruse in proximal zone 330 and distal zone 340, in some examples materialsmay be chosen such that proximal zone 330 has relatively low compliancecompared to intermediate zone 340 and distal zone 350.

A cross-sectional view of distal subassembly 400 is illustrated in FIG.4A. Enlarged portions of distal subassembly 400 are illustrated inpartial cutaway and cross-sectional views in FIGS. 4B-C, respectively.In the configuration illustrated in FIGS. 4A-C, distal zone 350 of outercatheter 300 surrounds many components of distal subassembly 400.Generally, distal subassembly 400 includes nut 410, an inner rotarycoupling 420, an outer rotary coupling 430, a proximal hub 440, and adistal hub 450.

Nut 410 may generally take the form of a cylindrical member withinternal threads configured to mate with threads on lead screw 250. Thethreads of nut 410 and lead screw 250 may have the same pitch. Nut 410may be bonded, adhered, or otherwise affixed to an inner portion ofdistal zone 350 of outer catheter 300 such that the nut is rotationallyand axially fixed with respect to the outer catheter. Nut 410 may beformed from various suitable materials, including biocompatible metalsand/or plastics. Although a nut is described, other fixed internallythreaded members may be used in its place. Nut 410 may also take theform of, for example, a split nut which may simplify manufacturingdelivery device 100.

Inner rotary coupling 420 may take the form of a generally cylindricalhollow member with a flanged proximal base. The distal end of lead screw250 is covered by inner rotary coupling 420, with the inner rotarycoupling being bonded, adhered, or otherwise affixed to the lead screwsuch that the inner rotary coupling is rotationally and axially fixedwith respect to the lead screw. A proximal end of inner rotary coupling420 may include an aperture through which lead screw 250 passes, while adistal end of the inner rotary coupling may include an aperture sized toallow the passage of guidewire 360 therethrough. At least the portion ofthe distal end of lead screw 250 that extends into proximal hub 440 iscovered by inner rotary coupling 420. In this configuration, the threadsof lead screw 250 do not directly contact proximal hub 440. Rather,inner rotary coupling 420, which may have a smooth outer surface, is incontact with proximal hub 440. Inner rotary coupling 420 may be formedof a low friction material such as polyoxymethylene (e.g. acetal), PTFE,or stainless steel with a lubricant such as silicon. The distal ends ofinner rotary coupling 420 and/or lead screw 250 abut an inner contactsurface of proximal hub 440. In this configuration, as lead screw 250and attached inner rotary coupling 420 are translated distally, thedistal ends of the inner rotary coupling and/or lead screw push againstthe inner contact surface of proximal hub 440, causing the proximal hubto translate distally. This function is described in greater detailbelow in relation to FIGS. 5A-C and FIGS. 6A-C.

Outer rotary coupling 430 may take the form of a generally cylindricalhollow member having a generally flat proximal end and a shaped distalend. The flat proximal end of outer rotary coupling 430 may include anaperture configured to allow passage of lead screw 250 therethrough. Thedistal end of outer rotary coupling 430 may be sized and shaped to matewith the shape of a proximal end of proximal hub 440. For example, ifthe proximal end of proximal hub 440 is generally convex, the distal endof outer rotary coupling 430 may be concave. These mating shapes mayfacilitate the fixation of outer rotary coupling 430 to a proximal endof proximal hub 440, through bonding, adhesives, or other means ofaffixation. In this configuration, outer rotary coupling 430 is axiallyand rotationally fixed with respect to proximal hub 440, but maytranslate axially with respect to outer catheter 300. Outer rotarycoupling 430 may be formed of a low friction material such aspolyoxymethylene (e.g. acetal), PTFE, or stainless steel with alubricant such as silicon.

As noted above, inner rotary coupling 420 may include a flanged proximalbase. This flanged proximal base may abut a contact surface of outerrotary coupling 430. The flanged proximal base may provide an increasedsurface area of contact between the proximal end of inner rotarycoupling 420 and the contact surface of outer rotary coupling 430. Theflanged base may also keep inner rotary coupling 420 centered in outerrotary coupling 430 while minimizing rotational friction between thetwo. As lead screw 250 and attached inner rotary coupling 420 aretranslated proximally, the flanged base of the inner rotary couplingforces outer rotary coupling 430 proximally. Because outer rotarycoupling 430 is fixed to proximal hub 440, the proximal hub is alsotranslated proximally as a result of the above-described motion. This isdescribed in more detail in relation to FIGS. 5A-C and FIGS. 6A-C.

Still referring to FIGS. 4A-C, proximal hub 440 and distal hub 450 maybe connected by an inner shaft 460. Inner shaft 460 may be a generallycylindrical hollow member configured to transmit axial motion ofproximal hub 440 to distal hub 450. Inner shaft 460 may be integrallyformed with proximal hub 440 and distal hub 450, or may be otherwiseaffixed to the proximal and distal hubs. Inner shaft 460 may be sized toallow passage of guidewire 360 therethrough.

In combination, proximal hub 440, distal hub 450, inner shaft 460, andthe distal zone 350 of outer catheter 300 define a compartment C inwhich a collapsible and expandable medical device, such as prostheticheart valve 500, may be stored in a collapsed configuration duringdelivery. It should be noted that, although collapsible prosthetic heartvalve 500 is depicted herein as a unitary solid member for clarity ofillustration, a typical prosthetic heart valve would take the form of aprosthetic valve mounted on a stent that is formed of a number ofinterconnecting struts. Proximal hub 440 may include one or moreretention features, such as cut-outs 442, having a trapezoidal,circular, or other shape corresponding to the shape of retentionfeatures 510 extending from the aortic end of prosthetic valve 500.During delivery, retention features 510 of prosthetic valve 500 arepositioned within cut-outs 442 and, as long as the distal zone 350 ofouter catheter 300 is positioned over the cut-outs, the prosthetic valveremains connected to delivery device 100. As is described in greaterdetail below with respect to FIGS. 6A-C, this configuration allowsprosthetic valve 500 to be resheathed back into compartment C after itspartial release.

Distal hub 450 may take the general form of a cylindrical body thattapers to an atraumatic tip 452 at a distal end. A proximal end ofdistal hub 450 may also be slightly tapered in the proximal direction,which may help the annulus end of prosthetic heart valve 500 to sitwithin compartment C more securely. Distal hub 450 may also include achannel therethrough sized and configured to allow passage of guidewire360 through the channel.

In an exemplary aortic valve replacement procedure, prosthetic heartvalve 500 is loaded within compartment C of distal subassembly 400, withretention features 510 of the prosthetic valve positioned withincut-outs 442 of proximal hub 440 and distal zone 350 of outer catheter300 entirely covering the collapsed prosthetic valve. An incision ismade in the patient at the point of intended entry which may be, forexample, through the femoral artery. If desired, guidewire 360 may beinserted into the incision and guided to the implant site. If guidewire360 is used, delivery device 100 may be threaded over the guidewire tofacilitate advancement of the delivery device to the implant site.Delivery device 100 is advanced through the vasculature and around theaortic arch until delivery subassembly 400 is positioned at or near theposition of the native valve annulus. Once the surgeon confirms thatdelivery subassembly 400 is in a desired position for releasingprosthetic valve 500, handle subassembly 200 may be operated to deploythe prosthetic valve. Prior to beginning deployment of prosthetic valve500, handle subassembly 200 is at an initial position with drive key 240at a proximalmost position, as illustrated in FIGS. 2A-B, and distalzone 350 of outer catheter 300 completely covering the collapsedprosthetic valve, as illustrated in FIG. 4A.

Handle subassembly 200 is illustrated in FIGS. 5A-C in incrementalstages of deployment. To begin deployment, the user rotates deploymentknob 220 in a first direction, causing spur gear 232 to rotate alongwith ring gear 222, which in turn causes center drive 230, drive key240, and lead screw 250 to all rotate. As the external threads of leadscrew 250 rotate in engagement with the internal threads of nut 410, thelead screw is pulled distally. The distal ends of lead screw 250and/inner rotary coupling 430 push against the inner contact surface ofproximal hub 440, causing the proximal hub and, hence, distalsubassembly 400, to move distally as well. Because of the configurationof inner rotary coupling 420 and outer rotary coupling 430, only axialmotion, and not rotational motion, of lead screw 250 is translated toproximal hub 440. Further, because lead screw 250 is pulled distally dueto the rotation of its threads relative to internal threads of nut 410,the entire outer catheter 300 does not need to be stiff enough to easilytransmit axial force along its entire length. In one embodiment, thedistal zone 350 of outer catheter 300 may be about 3 inches (7.62 cm)long. In this embodiment, only about 3 inches (7.62 cm) of the distalend of lead screw 250 is in tension and/or compression duringadvancement and/or retraction. FIGS. 5A, 5B, and 5C illustrate handlesubassembly 200 after an initial increment of deployment, anintermediate increment of deployment, and full deployment, respectively.In the current example, FIG. 5A represents about 0.375 inches (0.95 cm)of deployment, FIG. 5B represents about 1.5 inches (3.81 cm) ofdeployment, and FIG. 5C represents about 3 inches (7.6 cm) ofdeployment. It should be noted that drive key 240 contacts a distal endof handle housing 210, which provides a limit as to how far the drivekey may travel in the distal direction. The 3 inch length of distal zone350 of outer catheter 300 is merely illustrative of one possibleembodiment. Those of skill in the art should understand that differentlengths may be appropriate under different circumstances.

Distal subassembly 400 is illustrated in FIGS. 6A-C at positionscorresponding to those illustrated in FIGS. 5A-C. It should be notedthat in FIGS. 6A-C, distal zone 350 of outer catheter 300 is shown in apartial cutaway view to illustrate the components positioned within thedistal zone. At the initial increment of deployment, illustrated in FIG.6A, the annulus end of prosthetic valve 500 begins to extend beyond thedistal end of distal zone 350 of outer catheter 300 and begins to expand(expansion not illustrated in FIGS. 6A-C).

At the intermediate increment of deployment (shown in FIG. 6B), abouthalf of prosthetic valve 500 extends beyond distal zone 350 of outercatheter 300. At the initial and intermediate increments of deployment,and at any time before full deployment, the retention features 510 ofprosthetic valve 500 are trapped within cut-outs 442 of proximal hub 440and covered by a portion of distal zone 350 of outer catheter 300. Aslong as retention features 510 remain in this position, despite the factthat portions of prosthetic valve 500 may have already expanded, theprosthetic valve may be resheathed within distal zone 350 of outercatheter 300 by rotating deployment knob 220 in the opposite direction.The user may desire to resheath prosthetic valve 500 if, for example, itis determined that the placement of the prosthetic valve is notdesirable.

Distal subassembly 400 at full deployment is illustrated in FIG. 6C. Atthis point, prosthetic valve 500 is fully expanded at the implant siteand cannot be resheathed. The user may rotate deployment knob 220 in theopposite direction to pull distal subassembly 400 proximally back intodistal zone 350 of outer catheter 350. Because of the configuration ofinner rotary coupling 420 and outer rotary coupling 430, and inparticular the flanged base of the inner rotary coupling, proximalmovement of lead screw 250 causes proximal movement of proximal hub 440.As noted above in relation to FIGS. 4A-C, as lead screw 250 and attachedinner rotary coupling 420 are pulled proximally, the flanged base of theinner rotary coupling presses against the contact surface of outerrotary coupling 430, which is fixed to proximal hub 440. In thisconfiguration, proximal movement of lead screw 250 results in proximalmovement of proximal hub 440. Once distal subassembly 400 is fullypositioned within distal zone 350 of outer catheter 300, the user mayremove delivery device 100 and guidewire 360 from the patient,completing the procedure.

In another embodiment of the disclosure, an overlying sheath 600,illustrated in FIG. 7, may be used along with delivery device 100 toincrease the accuracy with which the distal end of the delivery deviceis placed at the implant site. Overlying sheath 600 may take the generalform of an elongated hollow cylinder extending from a proximal end 610to a distal end 620. Proximal end 610 may include an introducer hub 612.A distal portion 630 of overlying sheath 600 may be pre-shaped such thatthe distal portion is angled with respect to the remainder of theoverlying sheath. For example, distal portion 630 may be smoothly curvedas illustrated or otherwise angled, such as having an abrupt bend. Inthis configuration, overlying sheath 600 takes the form illustrated inFIG. 7 when no force is applied to the overlying sheath. In particular,a proximal portion of overlying sheath 600 may extend along a firstlongitudinal axis L₁, while distal end 620 of distal portion 630 extendsalong a second longitudinal axis L₂. First longitudinal axis L₁ may forman angle α with respect to second longitudinal axis L₂.

In use, overlying sheath 600 may be placed over delivery device 100prior to insertion into the patient, with distal end 620 of theoverlying sheath being positioned at, or just proximal of, the point oftransition between proximal zone 330 and intermediate zone 340 of outercatheter 300. Overlying sheath 600 may be formed of a material such asPebax, nylon, stainless steel braid, PEEK, Vectran, PTFE, or nitinol.The chosen material may have greater compliance than proximal zone 330of outer catheter 300 but lower compliance than intermediate zone 340 ofthe outer catheter. In this configuration, during advancement ofdelivery device 100 as described in relation to FIGS. 5A-6C, overlyingsheath 600 remains in a position over proximal zone 330 of outercatheter 300 during the majority of delivery, until the distal end ofthe delivery device is at or near the aortic arch. Because overlyingsheath 600 is more compliant than proximal zone 330 of outer catheter300, the overlying sheath takes the form of the proximal zone of theouter catheter. However, once at or near the aortic arch, overlyingsheath 600 may be advanced distally. As the pre-shaped distal portion630 of overlying sheath 600 advances from the less compliant proximalzone 330 to the more compliant intermediate zone 340 of outer catheter300, the pre-shaped distal portion reverts to its pre-formed shape. Asit does so, it will cause intermediate zone 340 to bend to substantiallythe same shape. This pre-formed shape may help center distal subassembly400 within the native annulus, which otherwise may be difficult becauseof the shape of the aortic arch.

In the illustrated embodiment, angle α between first longitudinal axisL₁ and second longitudinal axis L₂ is about 45°, but other angles may bedesirable. For example, angle α may be between about 15° and about 75°,between about 30° and about 60°, between about 35° and about 55°, orbetween about 40° and about 50°. Further, in the illustrated embodiment,distal portion 630 is about 1 inch (2.54 cm) long, but other lengths maybe desirable. For example, distal portion 630 may be about 0.5 inches(1.27 cm) long, about 1.5 inches (3.81 cm) long, about 2 inches (5.08cm) long, about 3 inches (7.62 cm) long, about 4 inches (10.16 cm) long,about 5 inches (12.7 cm) long, about 6 inches (15.24 cm) long, or anylength between about 0.5 inches (1.27 cm) and 6 inches (15.24 cm).

Although the invention herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent invention. It is therefore to be understood that numerousmodifications may be made to the illustrative embodiments and that otherarrangements may be devised without departing from the spirit and scopeof the present invention as defined by the appended claims. It will beappreciated that the various dependent claims and the features set forththerein can be combined in different ways than presented in the initialclaims. It will also be appreciated that the features described inconnection with individual embodiments may be shared with others of thedescribed embodiments.

According to one embodiment of the present disclosure, a delivery devicefor a collapsible medical device may include a handle having anactuation member; a delivery assembly having a compartment for receivingthe medical device; a catheter member extending from the handle to thedelivery assembly; an internally threaded member fixedly connected tothe delivery assembly; and an externally threaded member having a firstportion operatively connected to the actuation member and a secondportion threadedly coupled to the internally threaded member so thatmanipulation of the actuation member causes axial movement of thecompartment relative to the catheter member; and/or

the delivery assembly may further comprise a first hub connected at aspaced distance to a second hub, the externally threaded member beingoperatively connected to the first hub; and/or

the delivery device may further comprise a rotary coupling interposedbetween the externally threaded member and the first hub; and/or

the rotary coupling may include a first portion fixedly connected to theexternally threaded member and a second portion fixedly connected to thefirst hub, the first portion being rotatable relative to the secondportion; and/or

manipulation of the actuation member may cause axial movement of thefirst hub but may not cause substantial rotational movement of the firsthub.

According to another embodiment of the present disclosure, a deliverydevice for a collapsible medical device may include a handle; a deliveryassembly having a compartment for receiving the medical device; and acatheter member extending from the handle to the delivery assembly andhaving a first portion with a first compliance value and a secondportion with a second compliance value, the first compliance value beingless than the second compliance value; and/or

the first portion may be positioned proximally relative to the secondportion; and/or

the delivery device may further comprise a sheath having a proximalportion and a distal portion, the sheath being configured to bepositioned at least partially over the catheter member, a longitudinalaxis of the proximal portion is disposed at an acute angle with respectto a longitudinal axis of the distal portion when no force is applied tothe sheath; and/or

the sheath may have a third compliance value between the firstcompliance value and the second compliance value; and/or

the angle between the longitudinal axis of the proximal portion of thesheath and the longitudinal axis of the distal portion of the sheath maybe between about 15° and about 75°; and/or

the angle between the longitudinal axis of the proximal portion of thesheath and the longitudinal axis of the distal portion of the sheath maybe between about 35° and about 55°; and/or

the angle between the longitudinal axis of the proximal portion of thesheath and the longitudinal axis of the distal portion of the sheath maybe about 45°.

According to the present disclosure, a method for delivering a medicaldevice into a patient may include providing a delivery device includinga catheter member having a first portion with a first compliance valueand a second portion with a second compliance value greater than thefirst compliance value; advancing the catheter member to an implant sitewithin the patient; and at least partially releasing the medical devicefrom a compartment adjacent the catheter member; and/or

the method may further include positioning a sheath at least partiallyover the catheter member, the sheath having a distal portion that isdisposed at an acute angle with respect to a remainder of the sheathwhen no force is applied to the sheath; and/or

prior to the advancement step, the distal portion of the sheath may bepositioned over the first portion of the catheter member so that thedistal portion of the sheath is not disposed at an acute angle withrespect to the remainder of the sheath; and/or

the method may further comprise distally advancing the sheath withrespect to the catheter member prior to the releasing step so that thedistal portion of the sheath is positioned over the second portion ofthe catheter member; and/or

the step of distally advancing the sheath may cause the distal portionof the sheath to be disposed at an acute angle with respect to theremainder of the sheath; and/or

the method may further comprise centering the compartment within anative valve annulus of the patient prior to at least partiallyreleasing the medical device; and/or

the delivery device may further comprise a handle having an actuationmember and a delivery assembly at least partially defining thecompartment; and/or

the delivery device may further include an internally threaded memberfixedly connected to the delivery assembly and an externally threadedmember having a first portion operatively connected to the actuationmember and a second portion threadedly coupled to the internallythreaded member, wherein the releasing step may include rotating andaxially advancing the externally threaded member.

The invention claimed is:
 1. A delivery device for a collapsible medicaldevice, the delivery device comprising: a handle having an actuationmember; a distal catheter portion for receiving the medical device; acatheter member extending from the handle to the distal catheterportion, the catheter member fixedly coupled to the distal catheterportion; an internally threaded member fixedly connected to the distalcatheter portion so that the internally threaded member is rotationallyand translationally fixed with respect to the distal catheter portion; afirst hub fixedly connected to a second hub at a spaced distance, thefirst hub adapted to contact the collapsible medical device when thecollapsible medical device is received within the distal catheterportion; an externally threaded member having a first portionoperatively connected to the actuation member and a second portionthreadedly coupled to the internally threaded member so thatmanipulation of the actuation member causes axial movement of the distalcatheter portion relative to the first hub, and a rotary coupling havinga first portion translationally and rotationally fixed to the externallythreaded member, and a second portion translationally and rotationallyfixed to the first hub, the first portion being rotatable relative tothe second portion and translationally fixed relative to the secondportion, wherein the externally threaded member extends through a distalend of the handle and through substantially an entire length of thecatheter member.
 2. The delivery device according to claim 1, whereinmanipulation of the actuation member causes axial movement of the firsthub but does not cause substantial rotational movement of the first hub.3. A delivery device for a collapsible medical device, the deliverydevice comprising: a handle; a catheter member extending from a proximalend fixedly coupled to the handle to a distal end, the catheter memberhaving a proximal portion with a first compliance value, a distalportion at the distal end for receiving the medical device in acollapsed condition, and an intermediate portion positioned between theproximal portion of the catheter member and the distal portion of thecatheter member, the intermediate portion of the catheter member havinga second compliance value, the first compliance value being less thanthe second compliance value; and a sheath having a proximal portion anda distal portion, the sheath being configured to be positioned over boththe proximal portion of the catheter member and the intermediate portionof the catheter member, a longitudinal axis of the proximal portion ofthe sheath being disposed at an acute angle with respect to alongitudinal axis of the distal portion of the sheath when no force isapplied to the sheath, the sheath having a third compliance valuebetween the first compliance value and the second compliance value. 4.The delivery device according to claim 3, wherein the angle between thelongitudinal axis of the proximal portion of the sheath and thelongitudinal axis of the distal portion of the sheath is between about15° and about 75°.
 5. The delivery device according to claim 3, whereinthe angle between the longitudinal axis of the proximal portion of thesheath and the longitudinal axis of the distal portion of the sheath isbetween about 35° and about 55°.
 6. The delivery device according toclaim 3, wherein the angle between the longitudinal axis of the proximalportion of the sheath and the longitudinal axis of the distal portion ofthe sheath is about 45°.
 7. The delivery device according to claim 3wherein, in an assembled condition of the delivery device, the sheath isslidable relative to the catheter member.
 8. The delivery deviceaccording to claim 3, wherein the distal portion of the catheter memberhas an outer diameter that is larger than an outer diameter of theintermediate portion of the catheter member.